Clock supply apparatus

Abstract

A clock supply apparatus for supplying clock signals to a plurality of circuit blocks includes a supply unit configured to supply, to reset the plurality of circuit blocks, a clock signal rising at timing different from one circuit block to another to each of the plurality of circuit blocks.

What is claimed is: 
     
       1. A clock supply apparatus for supplying clock signals to a first circuit block and a second circuit block, the clock supply apparatus comprising:
 each of a first control signal generation unit and a second control signal generation unit configured to supply a first control signal and a second control signal; 
 a first clock control unit configured to input the first control signal supplied by the first control signal generation unit and to supply a first clock signal having an active edge phase, to reset the first circuit block, to the first circuit block in response to the first control signal; and 
 a second clock control unit configured to input the second control signal supplied by the second control signal generation unit and to supply a second clock signal having an active edge phase different from the active edge phase of the first clock signal, to reset the second circuit block, to the second circuit block in response to the second control signal. 
 
     
     
       2. The clock supply apparatus according to  claim 1 , wherein the active edge phase of the first clock signal supplied by the first clock control unit and the active edge phase of the second clock signal supplied by the second clock control unit are supplied to the first circuit block and the second circuit block, respectively, at different timings. 
     
     
       3. The clock supply apparatus according to  claim 1 , wherein the first clock control unit is configured to generate, by thinning clock pulses of an inactive period of the first control signal from a predetermined clock signal, the first clock signal, and the second clock control unit is configured to generate, by thinning clock pulses of an inactive period of the second control signal from the predetermined clock signal, the second clock signal. 
     
     
       4. The clock supply apparatus according to  claim 1 , wherein each of the first control signal generation unit and the second control signal generation unit is configured to generate, by thinning clock pulses of different periods from a predetermined clock signal, the first control signal and the second control signal. 
     
     
       5. The clock supply apparatus according to  claim 4 , wherein each of the first control signal generation unit and the second control signal generation unit includes a counter configured to count clock pulses of the predetermined clock signal during a resetting operation, and a circuit configured to generate the first control signal and the second control signal that become active during periods corresponding to different values indicated by the counter during the resetting operation. 
     
     
       6. The clock supply apparatus according to  claim 5 , wherein each of the first control signal generation unit and the second control signal generation unit includes a circuit having a plurality of flip-flops annularly connected in series, the plurality of flip-flops being operated in synchronization with the predetermined clock signal and including a flip-flop initialized to an active level according to a reversal signal of a resetting signal for resetting the plurality of circuit blocks and a flip-flop initialized to an inactive level according to the reversal signal of the resetting signal, and outputs output signals of the plurality of flip-flops as the plurality of control signals when the reset signal is at an active level.